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6 Sheets-Sheet 1 Nov.. 12, 1929. E. s. PEARCE ET Al.

` I MEANS FOR DPERATING LDCOMOTIVES Filed April s, 1923 l l Nov'. l2, 1929.- E. s. PEARCE Er AL- 1,735,087

- MEANS FOR OPERATING LQCOMOTIVES I Filed April 5. 192s e shts-sheet 2 mex P/ssms a/K F/rfssaff QZ' ENT wmf E. S. PEARCE ET AL MEANS FOR OPERATING LOGOMOTI'VES Filed April 3, 1925 6 Sheets-Sheet Nov'. 12, 1929.

A TTORNE Ys 7L j WITNESS v e sheets-sheet 4 E. S. PEARCE ET AL MEANS FOR OPERATING LOCOMOTIVES r11ed.Apri1 5. 1925 Nov. l2, 1929.

Nov. l2, 1.929. i E. s. PEARCE T AL 1,735,087

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MEANS FOR OPERATING LOC OMOT I VE S Filed April 5. 1923 6 Sheets-Sheet 5 WITNESS Nov. 12, 1929; E. s. PEARCE Er A1. 1,735,087

MEANS FOR OPERATING LOCOMOTIVES Filed April 5. 1923 6 Sheets-Sheet 6 Patented Nov. l2, 13929 tlttliil @STATES EDWIN s. PEARCE, RAYMOND W. RETTERER, AND EDMOND o. KARIBO, or IND-IAN- APoLIs, INDIANA Y r MEANS EOR OPERATING: LOCOMOTIVES Application led April 3,

This invention relates to means for automatically adjusting the cut olf of the locomotive valves and is in the nature of an improvement over the structure disclosed in our Letters Patent No. 1,595,571, issued August l0, 1926. More specificallystated the present invention relates to the provision of improved apparatus for automatically adjusting the cut off in relation to the back pressure developed on the exhaust side of the locomotive pistons.

In the Letters Patent referred to a brief analysis of the operation of a locomotive is given and the fact that there is a direct relation between speed, cut olf and back pressure,

all other conditions being the same, is pointed out. Exhaustive investigation has determined that, for a given class or type of locomotive, there is one particular back pressure valve, which, if held constant or substantially so by adjusting the cut ofi' as the speed varies, will insure the development of maximum horse power. In other words to obtain maximum horse power output a certain constant or substantially constant back pressure should be maintained regardless of speed.

For instance, in starting an engine from a dead stop, cut on' remaining the same, the

back pressure would increase as the speed increased and in order to reduce this back pressure it is necessary to shorten thecut off.

On the other hand, assuming that the locomotive is running at a given and a fair'rate of speed, cut off remaining the same, the back pressure will decrease with a decrease 1n speed.

Therefore, at the cost of some little repetition, we desire to state that it is the principal object of our invention toprovide an improved apparatus for maintaining a constant back pressure or a back pressure which is substantially constant by automatically adjusting the cut oif in relation to said back pressure.

To this end we provide a power engine for the operation of the locomotive power reverse gear, the operation of which engine is controlled by the back pressure. Furthermore we employ this power engine in such a way that it is unnecessary to utilize any of.

verse gear but in the present embodiment of our invention we aim to eliminate these special valves and to utilize the usual reverse gear valve as in the case of manual operation. In other words our device can take the form of a separate power plant which is under the control of the back pressure for operating the usual power reverse gear valve.

In developing our improved apparatus we employ a single member for causing the cut olf to be adjusted and for simultaneously controlling the direction in which such adjustment should be made, that is, shortened or lengthened.

It is also a principal object of thisinvention to provide for coarser adjustments in the longer cut oifs and finer adjustments in the shorter cut offs. This might be stated in other words by saying that we provide means for progressively adjusting the cut oif in greater amounts as the greatest cut olf is approached and in progressively lesser amounts as the least cut ofl' is approached. To this end weso constitute our power engine as to utilize its given stroke or degree of movement to effect coarser adjustments in the longer cut ods and shorter adjustments in the shorter cut offs.

We have also provided means for utilizing our automatic cut olf adjustment mechanism 8 in backward motion of the locomotive as well as in forward motion thereof.

It is a further object of our invention to so design our improved apparatus that it may be applied directly to locomotives of existing types without in any way destroying the present mode of controlling and operating such locomotives. We also arrange our apparatus so that it is possible to restore the usual hand control should this for any reason become necessary or desirable.

These together with such other objects as mayA appear hereinafter or are incident to our invention we obtain by means of a construc- CII tion which is illustrated in the accompanying drawings, wherein Fig. 1 is a diagrammatic side elevation of a locomotive with our improved controlling apparatus roughly indicated as applied thereto; Figs. 2, 3 and 4 indicate in more or less diagrammatic form the details and the manner of operation and the relation of the parts of our controlling mechanism; Fig. 5 is a side elevation partially in section of a detail of our invention taken on the line 5-5 of Fig. 6; Fig. 6 is a vertical cross section through some of the important parts of our improved mechanism; and Fig. 7 is a longitudinal vertical section through a power reverse gear which is particularly adapted for use with our invention. It should be noted in considering some of the figures, particularly Fig. 3, that the showing is to a very great extent diagrammatical as we found it very much easier to intelligibly and accurately describe our invention from such a diagrammatic drawing rather than from reproductions of the actual parts in their proper sizes, shapes and relation to one another. Ve also wish to direct attention to the fact that if Figs. 3 and 4 be placed side by side with Fig. 3 on the right and Fig. 4 on the left the parts on the two sheets will exactly align. This has been indicated by the heavy dot and dash line at the left of Fig. 3 and a similar line at the right of Fig. 4.

Referring to the drawings and first to Fig. l it will be seen that the locomotive 1 is equipped with a power reverse gear 2 which is subject to the manual control in the usual Wa y of the reverse lever 8 through the medium of the reach rod 4 and combination lever 19. In a manner well understood in this art the power reverse gear is adapted to be connected to the valve 8a by means of the reverse gear reach rod 6, reverse shaft arm 7, radiusrod hanger 7a, radius rod 7 b, link 7 0, lap and lead lever 7, and valve stem 8". Motion is imparted to the valve 8a also in a manner well known to the art by means of the eccentric crank 8, eccentric rod 8d and the union link 8e, the latter being connected between the cross head 8t and the lower end of the lap and lead lever 7d. The locomotive is driven, of course, through the medium of the usual piston 10a, piston rod 10b, cross head 8f, main rod 10, crank pin 10d, and side rod 10".

Live steam is admitted to the valve chests 8 through the usual supply pipes 9. Only one of each of these members as well as of the cylinders 10 and valve gear mechanisms above described are shown but it will be understood of course that there are two, one on each side of the locomotive. Air from the main reservoir 11 is supplied to the customary valve chest 12 through pipes 13 and 14 and the operation of the reverse gear which we prefer to use may be brieiiy described as follows. (See Fig. 7 and for a full description `reference may be had to our copending application Serial No. 570,182, filed J une 22, 1922,'in which certain novel features of the reverse gear are specifically claimed.)

The air from the pipe 14 enters the chamber 12a in which it is normally trapped, except when movement of the piston 2 is taking place. Should it be desired to set the locomotive valves 8fL for forward motion, the reverse lever (illustrated in its neutral position in Fig. 7) is moved to the right. This causes the rod 4 to be drawn toward the left and with it the upper end of the lever 19, the latter fulcruming during this operation upon the pivot 19a at its lower end. The rod19b extends from the pivot 19'n to the pivot 19C on the piston extension 2b. This movement of the lever 19 rocks the arm 19d on its shaft 19, the arm being rigid with the shaft, and being pivoted at 19g to the lever 19. The valve operating extensions 12b and 12C on the shaft are also moved, the former downwardly to close the exhaust valve 12d and open the inlet valve 12e, and the latter upwardly to open the exhaust valve 12f. Air will then iiow from chamber 12a into chamber 12g, past the check valve 12h, out through the pipe 12i and into the chamber 12j at the left of the piston 2a, thus forcing the piston 2a to the right. At the same time exhaust from the chamber 12k at theright of the piston will take place through pipe 121 and past valve 12f to the exhaust chamber 12m.

The foregoing action will be continued as long as the reverse lever 3 is being moved forwardly, but just as soon as this is stopped, the motion of the piston 2a, acting through its extension 2b, rod 19h, and lever 19, will return the valve operating extensions 12') and-12c to their neutral or horizontal position and the locomotive valves 8' will be held in the position of adjustment desired. Itis to be understood, of course, that the rod 6 is pivoted as at 6ZL tothe piston 2a and that motion thereof is transmitted to the reverse shaft arm 7 in the usual manner. v Y

When the reverse lever 3 is brought baci; or moved into the opposite or left hand corner, just the reverse of the foregoing operations are effected, viz, the rod 4 moves forwardly or to the right, the lever 19 swings to the right and with it the arm 19d, and the extensions 12b and 12c move upwardly and downwardly respectively. Valve 12- is' thereby closed. valve 120 opened, and valve 12D opened. Air passes into chamber 121, past check valve 12r and out through pipe 121 into the chamber 12k at the 'right of piston 2n. The piston 2a then moves to the left and the chamber 12j is exhausted through pipe 12, valve 12p and exhaust chamber 12s.

It will be understood, of course, that when the piston 2a moves the lower end of the lever v 19, it fulcrums at its upper end where the pivot 19t connects it to the rod 29 and through 7 the rod 20 to the reach rod 4. This is the well known mode of operation of the floating lever 19. Furthermore, it should be noted that when our improved automatic control of the valves 8' is functioning, the hand control through the reverse lever 3 is made inoperative, and such automatic control taires place through the lever 20, all as will further appear.

When the locomotive is in operation back pressure from the exhaust passages of the Y valve chests 8 is delivered to the gauge l5 through pipe 16 which divides as shown at the forwardV end of the locomotive so that a branch enters at each end of the valve chest 8. It will be understood of course that the connection to one valve chest only is shown but there is a sim'lar connection to the valve chest on the other side of the locomotive. Back pressure is also introduced into what we have termed our controller A by means of a connecting pipe 17. In the baclr pressure pipe 16 we have introduced what we have termed the pressure retaining valve B and the uniflow fitting C, the purpose and functions of which will be described more in detail hereinafter. The connecting pipe 17 receives its supply at a point on the far side of the uniflow7 fitting C.

The controller A already referred to contains the most, important parts involved in our invention all of which will be described more in detail as its various functions are considered. Suffice it to say at this time that air is supplied to this controller from the main reservoir 11 through the pipe 18 and that the controller'through the medium of the air so supplied and under the regulation of the back pressure introduced through the pipe 17 automatically actuates the valve ofthe power reverse gear to adjust the cut ofi". The controller is Vcoupled to the valve operating lever 19 of the power reverse gear (see Fig. 4) by means of the controller reach rod 20. The air pressure in passing from the reservoir 11 to the controller A is conducted through what we term the primary7 control valveD the purpose and function of which will be more fully described hereinafter although at the present time it `is desired to point out that, after passing through this primary control valve7 the air can reach the gauge r15 and also the reverse lever locking cylinder E depending upon the conditions obtaining as will be hereinafter described. The locking cylinder E will also be more fullv described at the proper time although it can-here be stated that this cylinder locks the quadrant 21 in a stationary position whenever the power reverse gear is manually controlled but permits free rotation thereof whenever the reverse gear-is automatically controlled by ourimproved apparatus. rllhe pressure is conducted to the gauge through a branch of the pipe 18 and to the locking cylinder E through the pipe 22. l/Vhen air reaches the gauge through the pipe 18 it throws the indicator to auto which means that the locomotive is under automatic control but when the air is exhausted from pipe 18 as will be described later the indicator will show hand7 which means, of course, that the locomotive is under hand control. (See Fig. 2.)

Live steam pressure from the dry pipe of the locomotive is conducted through the pipe 23 to the primary control valve D in which pipe is located the foot valve F, by means of which the entire automatic system can be thrown out of operation for the time being if such a condition becomes necessary or advisable. There is also a globe valve 24 in the pipe 23 which is for the purpose of shutting off completely the supply of live steam should repair, adjustment or replacement become necessary.

1n the practice of our invention we desire to maintain a substantially constant back pressure and to utilize any tendency that there may be to increase such baclr pressure for the purpose of shortening the cut o and any tendency that there may be to decrease such pressure for the purpose of lengthening the cut oil. It is also our intention to do this automatically and with equal facility in either forward or back motion of the locomotive. The means we have employed for accomplishing these ends will now be described in detail beginning on the supposition that the locomotive is standing still and that the engineman desires to start it in a forward direction. When the locomotive is standing Astill the reverse lever will assume the position indicated in Fig. 1 which is the neutral or central position. When it is desired to go forward the reverse lever will be moved into the forward corner which is the position indicated in Fig. l but when it is desired to go backward the reverse lever will be moved to just the opposite corner which position has not been illustrated because it involves simply'the reverse of everything that will be described in connection with forward motion.

Turning particularly to Figs. 2, 3 and 4 and with Fig. 4 arranged to the left of Fig. 3 as indicated in the beginning of this speciication it will be seen that after the reverse lever 3 is moved into the forward corner the reach rod l will be drawn backwardly andv also the reverse gear valve operating lever 19. This places the power reverse gear in the proper condition to give the longest cut off possible in forward motion in a manner which is well understood in this art and is therefore not described in detail nor illustrated. At t-he same time the controller reach rod 20 is drawn to the left and with it the operating rod 25 of the controller A. The

rod is slidably mounted in suitable guides 26. This motion of the rod 25 draws the pin or lug 27, which is iixedly secured to the rod, to the left also. The pin is surrounded with a roller 28 which rides in a V-shaped slot 29 in the vertically movable cross head 30, the latter being mounted in guiding standards 31. It will readily be seen that this action will move the cross head from its upper position illustrated in Fig. 5 to its lower position indicated in Fig. 4.

The upper portion of the cross head 30 is provided with a horizontally disposed slot 32 adapt-ed to embrace the roller 33 on the pin 34 which latter projects into the slot from what we have called our friction wheel 35. The friction wheel 35 is rigidly secured to the ratchet wheel 36 so that motion in one will cause motion in the other.

This initial movement of the reverse lever also bring stop members 37 against pawl 38 thereby moving plunger 39 against the expanding pressure of spring 40 to close valve 41 and open valve 42 for a purpose which will appear hereinafter.

It is desired to call attention to the fact that the pin 27 with its roller 28 moves from the center or lowermost portion of the V- shaped slot 29 to the left hand point of the V. If the reverse lever had been moved in the opposite direction or into the rear corner for backward movement of the locomotive the pin with its roller 28 would have moved from the lower portion of the V to the upper pointV of the right hand side thereof. In either case however the motion of the cross head 30 would be exactly the same, namely downwardly in its guiding standards 31. Motion of the friction wheel 35 and of the ratchet wheel 36 would also have been the same as already described. It will also be observed that during initial downward movement of the cross head the downward movement of the pin 33 with its roller 34 wouldl be considerably less than during final movement of the cross head. In other words it is possible to produce a gradually increasing degree of movement in these parts or a gradually decreasing amount of movement when the motion is in the reverse direction as will appear somewhat later.

After the reverse lever has been moved to the forward corner the next step in the operation of the locomotive is to open the throttle valve to admit steam pressure through the pipes 9 to the valve chests 8. From there, in

the manner well known in this art, it passes through the cylinders 10 and reciprocates the piston rods to drive the wheels of the locomotive. The throttle valve is not illustrated nor are other parts just mentioned for the reason that they do not form a part of the present invention and would simply complicate the drawings. After the throttle valve has been opened live steam pressure, as already specified, is conducted to the primary tion of which it will be seen that the steam y pressure enters the chamberv 43 and then passes down past the valve into the chamber 45. If it is desired to prevent communication between the two chambers and thereby cut off the supply of steam vto the primary control valve D the engineer merely steps upon the pedal 46 which forces the valve 44 upwardly against its seat. When pressure enters the chamber 43 it automatically closes the valve 47 against the pressure of spring 48. But when the pressure is relieved in chamber 43 it will be seen that the valve 47 will open thereby permitting whatever condensation has accumulated to pass down into the chamber 45 through the interior of the housing 49. When the engineer pushes down upon the pedal 46 to close the valve 44 he.

opens a port to the atmosphere immediately below the valve 44 and thereby makes it possible for the condensation to drip out. It -v will also be seen that whenever the pressureV in the chambers 43 and 45 are equal the valve 47 will be opened.

The first action of the steamon entering.

is released from the quadrant locking device` through the pipe 22, D-cavity 53 of the slide valve 52 and exhaust port 54.

At this point it should be notedthat when the locomotive is standing still and the reverse. lever is in the position indicated in Fig. 1 air pressure is admitted through the pipe 22 to the operating piston 55 in the reverse lever locking cylinder. This piston is then forced upwardly against the pressure of spring 56 to move the teeth 57 into engagement with the teeth 58 on the circular quadrant 21. (These. parts are clearly illustrated in Fig. 4 although the reverse lever would be in the position indicated in Fig. 1). When this lock is set the reverse lever can be moved manually in the usual manner but when the automatic control is functioning this lock is released so that the controller reach rod 2O may be free to move the reverse lever reach rod 4 and thereby the reverse lever 3 to thel out oli' manually the engineer may move the reverse lever 3 in the customary manner. Under such manual operation the rotatable quadrant 2l is firmly held in a fixed position by engagement of the teeth 57 with the teeth 58. But just as soon as automatic control of the cut ofi1 begins the teeth 57 are disengaged from the teeth 58 because the air is exhausted from below piston and the quadrant 21 is then free to rotate in one direction or the other as the reverse lever 3 is moved forward or backward by the automatic device.

rIhe air pressure having'reached the controller through the pipe 18 it enters a sort of reservoir or chamber 59 from whichV chamber as a sort of common supply chamber it performs a number of functions. In the first place it enters the friction brake cylinder 60 and forces piston 6l against the pressure of spring '62 upwardly thereby bringing friction brake 63 into contact with friction wheel 85. The wheel 35 and the parts attached thereto and associated' therewith are therefore held in a certain xedpos'ition for the time being.

The air pressure also and at the sameV time iiows through passages 64 and 65 into the chamber 66 from which chamber it reaches the chamber 67 through port 68 in slide valve 69, small connecting passage 70, circular passage'71` in the outside of the bushing 72 and passage-73.

Piston 74 is thereupon moved to the left and with it slide valve 7 5 which we have termed the cylinder supply valve, which establishes communication between passages 76 and77. i

Furthermore air pressure is conducted from the passage 64 into the chamber 78 between the two ends of the piston 79, and from the chamber 78 pressure can reach the chamber 80 at the left of piston 79 and also chamber 81 at the right of piston 79 through the medium of passages 82 and 83 respectively. In each passage 82 and 83 there is placed a needle valve 8 Escape of air from chamber 80 is prevented by means of the slide valve 85 in one direction and valve 86 in the other direction. The air in chamber 8l reaches passage 87 and chamber 88 in what we have termed the cut off shortening side of the distributing slide valve 85. From chamber 88 pressure flows through the small passage 89 into the chamber 90 below the diaphragm 91. rIhe area below the diaphragm 91 being larger than the area exposed to the pressure above the diaphragm, the diaphragm will consequently move upwardly as indicated in Fig. 3 and cause member 92 to move tightly against its seat and prevent movement of air pressure out through the exhaust ports 98.

Still further, air from chamber 59 will pass to chamber 94 at the upper end of operating piston 95 through ports 64 and 96, holding said piston in downward position at all times when air is not present in chamber 120. Air also passes from chamber 59 throughv ports 64 and 146 to cavity to the righty of valve 42, passing further as described in a later portion of this specification. 1 The description so far given might b summed up briefly as follows: I he reverse lever has been moved to the forward corner for forward movement of the locomotive, the locomotive throttle has been opened and the pressure of the live steam entering the locomotive valve chests has been employed to admit fluid pressure, preferably air as here described, to the mechanism embodying our invention. This fluid pressure has unlocked the circular quadrant, has applied the friction brake to the friction wheel, has moved the operating piston 95 to its lowermost position, has moved the cylinder supply valve to the proper position for admitting fluid to the opposite and larger end of the operating piston (as will appear shortly) and finally has conditioned the distributing valve 85 so that there will be a shortening of the cut off as soon as the back pressure rises to the predetermined value as the locomotive gets under way. It will be understood of course that in starting a locomotive from a dead stop the first movement of the valve mechanism must be in the direction of shortening the cut olf since in starting the longest cut off is customarily used. (If locomotive is started in a shorter cut ofl" it will immediately begin to adjust toward a longer one upon the opening of the throttle.)

As the locomotive picks up speed the back pressure will gradually rise until it reaches a certain predetermined value. This value may vary with different classes of locomotives and we have made our device adjustable so that by a little experiment the proper degree of back pressure consistent with greati est efhciency can be readily determined.

The back pressure enters the controller A through the pipe 17 as already described and, by reference to Fig. 3 it will be seen that it enters a chamber 105 to the left of a diaphragm 106. In reaching the chamber 105 it first passes through the pressure retaining valve B and then through the uniflow fitting C. The pivoted valve B1 is free to swing open under the influence of successive exhaust impulses and the pressure is trapped when the valve again swings shut except that which is allowed to return through by-pass port B2. As the locomotive picks up speed the exhausts occur in such close succession as to be more nearly continuous so that valve B1 becomes unnecessary. Accordingly we connect a cam member B3 to some point on the reverse gear shaft, preferably the link 7, by means of a rod B4 and the arm B5 so that when the reverse lever is hooked up as speed :increases the cam B3y will move to hold the valve B1 in open position. The valve B1 is intended to perform its pressure retaining function only while the cut olf is in its longest motion because it is only then that the exhaast impulses are so interrupted as tok make this necessary. Such a condition, for instance, occurs when the locomotive is startingup from a dead stop. At the low speed then existing the exhaust impulses are. far enough apart so that pressure in pipe 16 will goo from zero to the maximum. By trapping thepeak and bleeding olf through the p-ort`B a general average pressure is maintained. As speed picks up the exhaust pul- SatOIlS come closer together and automati-Y Gally average themselves to a suflicient degree to make valve B1 unnecessary. It is, therefore, pulled up out of the way by cam B? as described which has a sufficiently ex tendedL surface, to keep it out of the way even throughouty the movement of rod BAz during. reverse motion. XVe do not attempt to use the valve B1 during reverse motion since. ordinarily a locomotive ldoes not run backward suihciently to warrant thc additional complication in the apparatus to make this possible.

rl `he back pressure now enters the uniflow fitting C which is provided with a pai-r of cylindrical perforated members C1 and otherwise constructed for the purpose of ironing out all possible pulsations in the exhaust. lhen the predetermined pressure has been reached the diaphragm moves to the riglit against the pressure of the spring 107 the force of which may be adjusted by means of the threaded plug 108. This movement is imparted to the downwardly projecting arm 109 of a rocking member pivoted at 110 which is provided with two outwardly extending arms 111 and 112. Arm 112 actuates the cut oli' shortening side of the distributingvalve and arm 111 actuates the cut off lengthening side of the distributing valve. AS arm 109 moves to the right arm 112 moves upwardly thereby opening valve 113. immediately andl'suddenly lowers the pressure within the chamber thereby causing the member 92 toY leave its seat and open passage 87 and chamber 81 to the atmosphere through the ports 93. This exhaust of pressure from the chamber 81 decreases the pres sure therein to a point below that in the chamber 80 at the opposite end of Jthe piston 7 9 and consequently the piston 79 will move to the right carrying with it the slide valve 85.

The first port to be uncovered to the pressure of? the,l fluid in the chamber 78 is the one numbered 11st` which communicates with the chamber 80,L and; this is simply for the purpose of supplying acontinued pressure to the chamber 80 inordentoA ensurea prompt and This j vigorous motionof the piston 79 and valve 85.

The next port to. be uncovered by the slide valve 85 in its motion toward theright is the one which communicates with passage 767 bridge 117 closing exhaust port 115. and bridge 118 clos-ing the right hand branch 7 6 of passage 76 and passage 119 to exhaust. (It should be noted that passage 76 can communicate with the chamber 78. at two different places and when the inlet at the left of valve 85 is opened it is desired that the portl 7 6a at the right be closed to exhaust.)l Pressure in passage 76 communicates withv passage, 77 as already described and admits pressure tothe under face of operating piston which it will be noted upon examining lflig. 3 is. considerably larger than the upper ace. Y

The operating piston 95 will then move upwardly since the pressure in chamber 120 applies itself to a greater area than the pressure in chamber 94.

In moving upwardly the operating piston 95 carries withit the projecting lug or pin 121 which is connected to what wev call the operating spider 122 which is mounted for sliding movement up and down in the guides 123'. The spider is provided with two outstanding arms 124 and 125 each of which carries a ratchet, the one onv the right being number 126 and the one on the left being number 127. T he ratchets are spring held to engage the teeth inthe ratchet wheel 36 but only one ratchet at a time. can engage these teeth on account of the rocking guard. 128 which also has a right arm 129 and a left arm 130. To the upwardly projecting portion of this guard 128. there. is fastened a reach rod 131 connected by the piston rod 132 to the pis.- ton 133 normally held in its extreme righthand` position by means of the spring 134. By this means the guard'128 is rocked sliglitly to the right in order to lower the right-k hand arm 129 and raise the left-hand arm 130. The ends of the arms` are each provided with a substantially vertical face 135 and with a shorter diagonal face l136 immediately thereabove. The incline of the face 136 is toward the center line of the guard. As the spider 122 moves upwardly with the guard in the position shown in Fig. 4 ratchet 126 will move inwardly along the face 136 until its point engages the ratchet wheel 36. At the same time theratchet 127 simply rides up on the vertical or substantially vertical face 135 so that its point does not come in contact with the wheel 36. The ratchet wheel 36 is then turned counterclockwise for a distance corresponding to the stroke of the operating spider 122. The maximum distance that the ratchet can be turned would correspond to. the complete stroke of the spiderv 122 but this distance can be lessened by altering the position of the memben128 with its gnardarms 129Vand 130.

l'lO

In order to accomplish this we provide the adjusting sleeve 133a threaded into one `end of the cylinder 133b in which the piston 133 reciprocates and also the set screw 133c at the other end of the cylinder. It is obvious that by reducing the travel of this piston the ends 129 and 130 of guard 128 will not travel to their lowest positions and, therefore, the ratchets 126 and 127 will not engage the ratchet wheel 36 for such a great distance.

This moves pin 34 upwardly and with it the cross head 30 and since the cross head can move only in a vertical direction the rod 25 and the connecting rod 20 are pulled to the right since the pin 27 with its roller 28 must follow the inclined groove of the V slot 29. Valve operating lever 19is moved to the right to actuate the valve in the valve chest 12 of the power reverse gear in such manner as to shorten the cut ofi".

During the upward movement of the operating piston 95 the pin 137 which it carries comes in contact with the slide valve 69 in the chamber 66 and moves it upwardly also.

the pressure in'the chamber 67 is exhausted to the atmosphere through the passage 73, connecting passage 70, channel 71, cavity 139 and passage 140. The pressure on the left of piston 74 thereupon -moves said piston to the right and closes off communication between the passages 7 6 and 7 and at the same time exhausts the pressure in the chamber 120 at the lower end of the operating piston 95, said exhaust takingy place through the passage 77, cavity 141 in the slide valve 75, port 154, 142 and at times port 100 as explained below. The latter port is capable of functioning only during initial movement of the reverse gear from its full forward stroke because shortly after the cut off begins to shorten, pin 101 will enter slot 102 in the right hand end of operating rod of the controller which slot runsv diagonally upwards at first and afterwards horizontally. When the pin 101`enters this slot 102 it will readily be seen that the passage through the valve 99 will be closed because it will have been rotated out of line with passage 98. Adjustment can be 50 made by means of the screw 102a acting to pinch the forked ends 103 against the interior cylindrical portion. The needle valve 104 is for the purpose of adjusting the speed at which the pressure will flow through passage 55 98 and valve 99. After valve 99 has closed,

the entire exhaust ofchamber 120 must pass out through port 142 and by adjusting the needle valve 97 the speed or the rapidity of motion of they operating piston 95 can be con- 60 trolled. If the needle valve is almost shut it will take several seconds for the air in the chamber 120'to exhaust. But while exhaust can take place through both passages v98 andV Vxhen the stroke of the piston is completed As long as it is necessary to keep shortening the cut olf, namely as long as theV back pressure tends to mount higher thanthe eertain predetermined pressure desired, this action will continue and the cut oif shortened until such time as the back pressure remains constant.

The foregoing operation will gradually move the pin 34 on the ratchet wheel 36 upwardly and at the same time toward the center line so that each step in the shortening movement will shorten thecut off a gradually decreasing amount inasmuch'as the upwardy movement of the pin 34 will decrease as the horizontal movement increases. This gives a coarser adjustment at such times when the out 0E is in its greater position and a finer adjustment as it approaches the lesser position. Y

It should also be noted that after the first movement of the ratchet wheel 36 counterclockwise the lug 37 moves away from the pawl 38 and thereby permits valve 42 to close and 41 to open to exhaust. This permits the pressure on the left-hand side of the stop valve piston 143 to exhaust to the atmosphere through passage 144 and exhaust port 145. Pressure had previously forced the piston 143 to the right through the passages 146 and 144 thereby seating valve 86 on the righthand side and unseating it on the left-hand side. By relieving the piston 143 of pressure on the left-hand side the valve 86 will be moved to the left and pressureY in the chamber 30 can come down past said valve and enter the passage 147. The closing of valve 41 and opening of valve 42 by the action of stop 37 against pawl 38 occurs only when the longest cut off is desired, as, for instance, when starting the locomotive from a dead stop. The ratchet wheel 36 has then reached the limit of its clockwise rotation and its next movement must be counterclockwise or in a direction which will release pawl 38 and permit valve 41 to open and valve 42 to close.

The purpose of the valves 41 and 42 is to admit or to exhaust air at the left of piston 143. When starting the locomotive there is, of course, no back pressure until motion and exhaust actually begin so that the diaphragm 106 will be moved to its extreme left hand position by the power of spring 107., At such times the lever 111 will be pushed upwardly and the valve 150 unseated, a condition which under ordinary operating circumstances would produce'lengthening of the cut off as described. But since the longest possible cut off already exists under the conditions presumed no further lengthening is possible and in order to stop the device and prevent waste of air the valve 86 is seated in its right hand position by the action of the pressure on piston 143. But just as soon as the back pressure developsto the point for which the device is set shortening of the cut off will begin with its incidental countercloclrwise rotation of wheel 36. This immediately releases the pressure from behind piston JM3, the exhaust taking place through valve L11. Then when the first lengthening motion is required valve 86 can freely unseat at the right and seat at the lett so that exhaust of air through passages 147 and 148, which is necessary to such operation, can take place.

As long as the arm'112 is moved upwardly and arm 111 downwardly, which is thecondition supposed throughout the foregoing description and not the condition illustrated in Fig. 3, the pressure will pass down through the bleed port 1118 to the underside of the diaphragm 149 causing said diaphragm to move upwardly since the area below it is greater than the area exposed to pressure above it. In this condition valve 150 is closed and communication between passage 1117 and the atmosphere through passage 151 is cut ott because the member 152 is in its upward positionagainst its seat 153.

After the cut ott has been shortened soinewhat, should the acceleration of the train cease, and train be running at approximately a steady speed, the spring 107 due to reduction in back pressure brought about by last shortenirnr adjustment ot cut oil made, will move arm 109 slightly to the lett, allowing valve 113 to seat and diaphragm -91 will move the member 92 upwardly against its seat so that exhaust from passage 87 will be cut ofi. -This allows air in chamber' 81 to build up to the saine pressure to which chamber is charged, and spring 155 which was compressed when valve was moved to the right, now moves the said valve to central position, bringing the entire controlling mechanism to rest.

It for any reason, the speed of the locomotive decreases, the back pressure will also decrease and spring 107 will move arm 109 farther to the lett, first taking up slight clearance between end of arm 111 and valve 150 and then raising said valve. Pressure below 'the diaphragm 149 will thereby be suddenly reduced, allowing member 152 to exhaust air :trom passage 1417 through the exhaust ports 151. Due to the above, pressure which will he suddenly reduced in chamber 80, willL permit the piston 7 9 to be moved to the lelt by the greater pressure in chamber 81. This motion is exactly the reverse of the motion which tool; place before.

As the slide valve 85 is carried to the lett by the piston 79 pressure will intially enter the chamber 81 in order to lreep up a goed supply in this chamber and ensure a prompt movement of the piston to the lett. After this, pressure will be introduced to the l -sage 76 and then to the chamber 120 below the operating piston in the manner betere indicated when the cut oli was being shortened and also to the passage 119 to the righthand end of the piston 133. The piston 133 will thereupon move to the left and rock the guard 128 to the left raising the right-hand arm 129 and lowering the left-hand arm-130. As the operating piston 95 moves upwardly the ratchet 127 will engage the ratchet wheel 36 and the ratchet 126 will ride against the substantially vertical face 135 and thus be held away from the wheel 36. From this it will be seen that the wheel 36 will be rotated in a clockwise direction, that the pin 34 will be moved downwardly and with it the cross head 30 which, acting upon the pin 27 in the slot 29 will move the operating rod 25 to the lett. This actuates the valve operating lever 19 to move the valve in chest 12 of the power reverse gear to lengthen the eut oit.

Furthermore, the cut otf will be lengthened continuously step by step in gradually increasing amounts until such time as the back pressure once again assumes the predetermined constant value desired. y

It is desired to pointout that this constant back pressure does not vary extensively as might be assumed from this description. A ditt'erential ot', for instance, one pound is permitted by the clearance allowed between the ends ot arms 111 and 112 and the valves 113 and 150. For instance, if back pressure to be carried is ten pounds, the controller is setto shorten cut oil' at ten and one-half pounds and lengthen it at nine and one-half pounds. Between these pressures valves 113 yand 150 are both closed and device is at rest. The adjustment is a step by step operation which is continuous as long as back pressure is above or below setting of controlling member.

As previously pointed out, our improved out oli controlling mechanism will operate just as well in backward motion of the locomotive as in forward motion. The only difference is that in backward motion the pin 27 with its roller 28 will ride up and down in the right hand side of the Vshaped slot 29. It is therefore thought unnecessary to describe in detail the operation of the device in reverse motion.

To sum up the operation ot the apparatus without referring to the passages by number, it might be stated in the first place that our controller A taken as a whole is .in edect a small engine operated by fluid pressure, preferably air. After the reverse lever has been moved into one corner or the other and the throttle o1 the locomotive opened, air pressure isbrought to this controlling engine ready for utilization as soon as the back presiio quire. In forward motion of the locomotive motion to the right of the operating rod 25 will cause the cut off to shorten and motion to the left will cause it to lengthen. In reverse lmovement of the locomotive, motion to the right will cause the out olf to lengthen and Ymotion to the left will cause it to shorten.

lt will be seen that we have provided many new features and these will be specifically pointed out in the claims below.

l. ln a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, and'a baclr pressure controlled actuating mechanism for said valve means, said actuating mechanism including means for moving said valve means so as to produce a shortening of the cut-off of the usual locomotive valves when the back pressure rises vaboveV a predetermined point, and means for moving said valve means so as to produce a lengthening` of the cut-off of the usual locomotive valves when the back pressure falls below said predetermined pointA 2. In a locomotive,the combination with the usual cylinders, pistons, valves, valve gears and exhaust, of means for effecting a step by step 4shortening of the cut-off of the usual valves, means causing a progressive decrease in the size of each step, means for effecting a step by -step lengthening' of said cutoff, means causing a progressive increase in the size of each step, and pilot means subject to the influence of back pressure for causing the shortening means to function when the bach pressure rises above a predetermined point and for causing the lengtheningmeans to function when the back pressure falls below said point.

3. In a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, Yoperating valve means therefor, and a back pressure controlled actuating mechanism for said valve means, said actuating mechanism including means for moving said valve means so as to produce a shortening of the cut-off of the usual locomotive valves when the back pressure rises above apredetermined point, and means for moving said valve means so as to produce a lengthening of the cut-ofi' of the usual locomotive valves when the back pressure falls below said predetermined point, together with means for causing the shortening movement to take place in gradually decreasing increments and the lengthen ing movement in gradually increasing increments. I l

4. ln a locomotive, the combination with the usual cylinders, pistons, valves, valve gear steam supply and exhaust, of a power reverse gear, operating valve means therefor, a motor device for actuating said valve means, aback pressure pilotdevice for automatically controlling the operation of said motor device, a second pilot device for preventing operation of said motor device when the locomotive is not using steam, means for applying pressure of operating steam from the said steam supply to said second pilot device when the locomotive is using steam whereby to permit operation of said motor device. and a valve adapted to control the Y steam so applied to said second pilot device whereby said steam may be temporarily cut olf at the volition of the engineer.

5. In a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a uni-directional motor for actuating said valve means, means for translating the motion of said uni-directional motor into movement of said valve means either for shortening or for lengthening the cut-off of the locomotive valves, and means subject to the influence of the bach pressure for initiating the translated motion of said motor for shortening the cut-olf when the back pressure rises above a predetermined point and for initiating the translated motion of said motor for lengthening the cutoff when the back pressure falls below said point.

G. lu a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, and a Huid actuated motor for operating said valve means comprising an operating reach rod, a fluid actuated reciprocating piston for moving said reach rod to successively shorten thecut-o, means for reducing the speed of piston reciprocation as shorter cut-offs are approached, and a pilot means subject to back pressure for causing said motor to shorten the cutoff when the back pressure rises above a predetermined point.

7. ln a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, and a fluid actuated motor for operating said valve means comprising an operating reach rod, a wheel for moving said reach rod, means connecting said reach rod and said wheel, means for rotating the wheel in one direction to shorten the cut-off, means for rotating it in the opposite direction to lengthen the cut-od, and a back pressure governed pilot device in control of said fluid actuated motor adapted to initiate rotation of said wheel to shorten the cut-off when the back pressure rises above a predetermined point and to lengthen the cutoff when it falls below said point.

8. ln a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a motor device for actuating said valve means which includes cut-off shortening apparatus, cutoff lengthening apparatus and a common back pressure governed pilot means controlling said motor device for causing actuation of the shortening apparatus when the back pressure rises above a predetermined point and of the lengthening apparatus when it falls below said point.

9. In a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a back pressure controlled actuating mechanism for said valve means, a conduit for supplying back pressure from said cylinders to said actuating means, a check valve in said conduit, and means for maintaining said check valve in open position except during times of substantial maximum cut-off.

10. In a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a reach rod for actuating Said valve means, a wheel for moving the reach rod to cause adjustment of the cut-oli, a motor device for turning the wheel, means for holding said wheel in each positien of adjustment, and a pilot device subject to the influence of cylinder back pressure for causing said motor to turn the wheel in one direction to shorten the cut-off when the back pressure rises above a predetermined point and to turn the wheel in the opposite direction to lengthen the cut-off when the back pressure falls below said point.

11. Ina locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operlating valve means therefor, a motor device for actuating said valve means to cause adjustment of the cut-off, means for holding the motor device in each position of adjustment, and a pilot device subject to the influence of back pressure for causing said motor device to actuate the valve means to shorten the cut-ofi' when the back pressure rises above a predetermined point and to lengthen the cut-off when the back pressure falls below said point.

12. In a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a reach rod for actuating said valve means, a wheel having a crank pin, a motor for turning the wheel, a pin on the reach rod, a cross head having a slot engaging the crank pin and a V-shaped slot engaging the pin on the reach rod, and a pilot device subject to the influence of back pressure for causing said motor to turn the wheel and reciprocate the crosshead through the medium of the crank pin and its engaging slot whereby one side of said V-shaped slot will act on the reach rod pin to move the reach rod so as to cause an adjustment which will shorten the cut-off when the back pressure rises above a predetermined point and the other side of said slot will act on the rearward pin to cause an adjustment which will lengthen the cut-olf when the back pressure:

falls below said point.

13. In a locomotive, the combination with the usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a reach rod for actuating said valve means, a pin on the reach rod, a member mounted for reciprocation in a direction substantially transverse that of the reach rod, a V-shaped slot in said member engaging the pin, one side of the V being adapted to engage the pin in forward motion of the locomotive and the other side in backthe usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear, operating valve means therefor, a reach rod for actuating said valve means, a ratchet wheel for moving the reach rod, and a motor device for turning the ratchet wheel, said motor device including a ratchet for rotating the wheel to initiate a shortening of the cut-olf, a ratchet for rotating the wheel to initate a lengthening of the cut-off, a piston for actuating the ratchcts, movable guard means for permitting only one ratchet at a time to function, and a pilot device subject to the influence of back pressure for moving the guard means so as to permit the shortening ratchet to function when the back pressure rises above a predetermined point and the lengthening ratchet to function when the back pressure falls below said point.

15. In a locomotive, the combination with t-he usual cylinders, pistons, valves, valve gear and exhaust, of a power reverse gear,- operating valve means therefor, a motor device for actuating said valve means, a selection device for causing the motor device either to shorten or to lengthen the cut-off, and a pilot device subject to the influence of back pressure for initiating actuation of the motor and for conditioning the selection device to cause shortening of the cut-olf when the back pressure rises above a predetermined point and for initiating actuation of the motor and for conditioning the selection device to cause lengthening of the cut-off should the back pressure fall below said point.

16. An apparatus for automatically maintaining a substantiall Y constant bac-lz` pressure f in a locomotive, comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear for adjusting the cut-ofi of the locomotive valves, operating valve means for said reverse gear, a motor mechanism for eiecting a step by step actuation of said reverse gear valve means, said motor mechanism including means for eilecting actuation of said operating valve means to shorten the cut-oft1 by progressively shorter steps and lengthen it by progressively greater steps in either forward or backward motion of the locomotive, and a pilot device subject to the influence of back pressure for causing said motor mechanism to shorten the cut-olf should the back pressure rise above a predetermined point and to lengthen the cut-oit should the back pressure fall below said point.

17. An apparatus for automatically maintaining a substantially constant back pressure in a locomotive, comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear 'for adjusting the cut-olf of the locomotive valves, opera-ting valve means for said reverse gear, a motor mechanism for actuating` said -reverse gear valve means, said motor mechanism including means for effecting actuation of the operating valve means to shorten the cut-oli" by progressively shorter steps and to lengthen it by progressively greater steps,

and a pilot device subject to the influence of back pressure for causing said motor mechanism to shorten the cut-off should the back pressure rise above a predetermined point and to lengthen the cut-oft should the back pressure fall below said point.

18. A cut-off adjusting apparatus for locomotives comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear, operating valve means for said reverse gear, a fluid actuated motor, means for causing said motor to move said operating valve means to eect a lengthening of the cut-off, means for causing said motor to move said operating valve means to effect a shortening of the cutoff, a valve :for controlling the fluid for a lengthening operation, a valve for controlling the fluid for a shortening operation, a member moved by the back pressure when it rises above a predetermined point for opening the valve which is in control of the fluid for a shortening operation, and means for moving said member in the reverse direction when the back pressure falls below said point to open the valve which is in control of the fluid `for a lengthening operation.

19. A steam locomotive having in combination with the usual valves and valve gear for controlling the supply and exhaust of the steam, a power reverse gear, operating valve means for said reverse gear, a motor for actuating said operating valve means, a pilot device for controlling said motor, and means for subjecting the pilot device to the influence of the back pressure on the exhaust side of the locomotive valves, said pilot device acting to cause motor operation which will move the operating valve means of said reverse gear to ellect a shortening of the cut-off when the back pressure rises above a predetermined point and to effect a lengthening of the cut-ofi' when it tends to fall below said point.

2O.4 A steam locomotive having in combination with the usual valves and valve gear for controlling the supply and exhaust of the steam, a power reverse gear, operating valve means for said reverse gear, a motor for actuating said operating valve means to effect a shortening of the cut-olf in successive steps, and means for reducing the speed of said motor as shorter cut-offs are approach/ed.

2l. A cut-0H adjusting apparatus for locomotives comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear, operating valve means for the reverse gear, a reach rod connected to the operating valve means, a wheel for moving the reach rod, means for revolving the wheel in one direction to cause said operating valve means to ellect a shortening of the cut-off, a second means for revolving the wheel in the opposite direction to cause said operating valve means to effect a lengthening of the cut-oit, a motor for actuating both of said revolving means, a movable guard device for preventing one of said means from functioning when the other one is being utilized, and a pilot device subject to the influence of the back pressure for moving said guard to prevent the lengthening means from functioning when the back pressure rises above a predetermined point and for moving said guard to prevent the shortening means from functioning when the back pressure falls below said point.

22. An apparatus for maintaining a substantially constant back pressure on a locomotive comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear, a motor for actuating said reverse gear, and a pilot device subject to the influence of the back pressure for initiating motor operation to hook back the reverse gear when the back pressure rises above a predetermined point and to advance it when the back pressure falls below said point.

23. An apparatus for maintaining a substantially constant back pressure on a locomotive comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear, a motor for actuating said reverse gear in successive steps, a pilot device subject to the influence of the back pressure for initiating motor operation to hook back the reverse gear when the back pressure rises above a predetermined point and to advance it when the back pressure falls below said point, and means causing a series of hooking back movements to take place in progressively shorter steps and vice versa.

24. An apparatus for maintaining a substantially constant hack pressure on a locomotive comprising in combination with the locomotive cylinders, pistons, valves, valve gear and exhaust, a power reverse gear, and motor mechanism for actuating said reverse gear, said motor mechanism including a reach rod connected to the gear, a reciproeating member for moving` the reach rod in one direction to Cause lengthening of the cut off and in the other direction to cause shortening of the cut oit, means for causing such movement to take place in a series of gradually increasing steps in the lengthening direction and in a series of gradually decreasing steps in the shortening direction, and

, a pilot device subject to the influence of the hack pressure for causing a lengthening of' the cut off when the back pressure falls below a predetermined point and a shortening when the back pressure rises above said point. In testimony whereof we have hereunto signed our names.

EDl/VIN S. PEARCE. RAYMOND W. RETTERER. EDMOND C. KARIBO. 

